Touch pen

ABSTRACT

A touch pen includes a body and a head fixed on one end of the body and electrically connected with the body. The head includes a number of carbon nanotubes. The number carbon nanotubes are stacked and crossed with each other, and joined by van der Walls attractive force and form a freestanding structure.

RELATED APPLICATIONS

This application claims all benefits accruing under 35 U.S.C. §119 fromChina Patent Application No. 201010607325.8, filed on Dec. 27, 2010, inthe China Intellectual Property Office, incorporated herein byreference.

BACKGROUND

1. Field of the Invention

The present disclosure relates to touch pens and particularly, to atouch pen used on touch panels.

2. Discussion of Related Art

Following the recent advancement of various electronic apparatus, suchas mobile phones, car navigation systems toward high performance anddiversification, there has been a growing number of electronicapparatuses equipped with optically transparent touch panels at thefront of their respective display devices (e.g., liquid crystal panels).

Touch pens are good input apparatuses to touch panels. To maintain itsportability, the touch pens cannot have large sizes. To obtain goodconductivity, the touch pens conventionally have a pen tip made ofmetals. However, the pen tip made of metals can damage the touch screenof the touch panels.

What is needed, therefore, is to provide a touch panel with soft pentip.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the embodiments can be better understood with referencesto the following drawings. The components in the drawings are notnecessarily drawn to scale, the emphasis instead being placed uponclearly illustrating the principles of the embodiments. Moreover, in thedrawings, like reference numerals designate corresponding partsthroughout the several views.

FIG. 1 is a schematic structural view of a touch pen of one embodiment.

FIG. 2 is a schematic view of a pen body of the touch pen of FIG. 1.

FIG. 3 is a cross-sectional view of one embodiment of a pen head.

FIG. 4 is a cross-sectional view of another embodiment of a pen head.

FIG. 5 is essentially a schematic view of another one embodiment of apen head.

FIG. 6 is a schematic view of a graphene.

FIG. 7 is a schematic view of a graphene composite material used as acontact layer of the pen head of one embodiment.

FIG. 8 is another graphene composite material used as a contact layer ofthe pen head of one embodiment.

FIG. 9 is a schematic view of a carbon nanotube composite layer used asa contact layer of the pen head of one embodiment.

FIG. 10 is a schematic view of a carbon nanotube composite layer used asa contact layer of the pen head of another embodiment.

FIG. 11 is a schematic view of a carbon nanotube composite layer used asa contact layer of the pen head of another one embodiment.

FIG. 12 is a Scanning Electron Microscope (SEM) image of a drawn carbonnanotube film.

FIG. 13 is an SEM image of a carbon nanotube structure including atleast two stacked carbon nanotube films.

FIG. 14 shows an SEM image of a flocculated carbon nanotube film.

FIG. 15 shows an SEM image of a pressed carbon nanotube film.

FIG. 16 is a schematic view of a pen head including a carbon nanotubewire structure located on an outer surface of a supporter according toone embodiment.

FIG. 17 is a schematic view of a pen head including a plurality ofcarbon nanotube wire structures located on the outer surface of asupporter according to one embodiment.

FIG. 18 is a schematic view of a carbon nanotube wire structureincluding a plurality of carbon nanotube wires parallel with each otherin one embodiment.

FIG. 19 is a schematic view of a carbon nanotube wire structureincluding a plurality of carbon nanotube wires twisted with each otherin one embodiment.

FIG. 20 is an SEM image of an untwisted carbon nanotube wire.

FIG. 21 is an SEM image of a twisted carbon nanotube wire.

FIG. 22 is a cross-sectional view of a carbon nanotube composite layerin one embodiment.

FIG. 23 is a cross-sectional view of a carbon nanotube composite layerin another embodiment.

FIG. 24 is a cross-sectional view of a carbon nanotube composite layerin another one embodiment.

FIG. 25 is a schematic view of a carbon nanotube composite layer used insome embodiments.

FIG. 26 is a schematic view of a carbon nanotube composite layer used insome other embodiments.

FIG. 27 is a schematic view of a touch pen with a Chinese brush shapepen head in one embodiment.

FIG. 28 is a schematic view of the pen head in FIG. 27.

FIG. 29 is a schematic view of a touch pen with a brush-shaped pen headin one embodiment.

FIG. 30 is a schematic view of a touch pen with a pen head made of thecarbon nanotube composite layer in another one embodiment.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate at least one embodiment of the present touch panel anddisplay device using the same, in at least one form, and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

Reference will now be made to the drawings to describe, in detail,embodiments of the present touch pen.

The disclosure is illustrated by way of example and not by way oflimitation in the figures of the accompanying drawings in which likereferences indicate similar elements. It should be noted that referencesto “an” or “one” embodiment in this disclosure are not necessarily tothe same embodiment, and such references mean at least one.

Touch Pen

Referring to FIG. 1, a touch pen 100 in one embodiment includes a penhead 120 and a pen body 110. The pen head 120 is fixed on one end of thepen body 110. The pen head 120 is soft and electrically conductive.

The pen body 110 is for users to hold the touch pen 100. The pen body110 is electrically connected with the pen head 120. The pen body 110can conduct electrons from users' hand to the pen head 120. When the penhead 120 contacts a touch panel in application, the contact region ofthe pen head 120 can be detected by the touch panel.

Referring to FIG. 2, the pen body 110 can be, but not limited to, atubular structure and includes a fixing end 114. The fixing end 114 mayhave a hole with an internal thread in one embodiment. The pen head 120can be designed for insertion through the hole of the fixing end 114 andelectrically connects the pen body 110. It is understood that, to makethe pen body 110 electrically connect with the pen head 120, theconnecting means of the pen body 110 and the pen head 120 is not limitedto the way described above.

Referring to FIG. 3, in one embodiment, the pen head 120 includes asupporter 121 and a contact layer 125. The contact layer 125 is attachedon an outer surface of the supporter 121. The supporter 121 can be madeof flexible materials, such as polymer. The contact layer 125 can bemade of flexible conductive materials. A shape of the pen head 120 canbe designed according to actual needs and can be, but not limited, tospherical shape or cone shape. In one embodiment, the pen head 120 has acone shape. Because the pen head 120 is flexible, a contact area betweenthe contact layer 125 of pen head 120 and the touch panel can becontrolled by pressure applied on the pen head 120. To control the widthof the line shown on the touch panel when the pen head 120 contacts withand moves on the touch panel, a contact capacitor between the pen head120 and the touch panel is proportional to the contact area between thepen head 120 and the touch panel. Therefore, the width of the line shownon the touch panel can be controlled by the pressure applied on the penhead 120 when the pen head 120 contacts and moves on the touch panel.The pen head 120 can be used to paint different styles of paintings orhandwritings on the touch panel. It is understood that the pen head 120may have different shapes according to different painting or handwritingstyles. The pen head 120 can be in a shape of a Chinese traditionalhandwriting pen or a brush used in oil painting.

Supporter

In one embodiment, the supporter 121 includes a fixing section 122 and amain section 124. An external thread is defined on an outer surface ofthe fixing section 122, which corresponds to the preformed internalthread of the fixing end 114 of the pen body 110. The fixing section 122is used to fasten the pen head 120 to the fixing end 114 of the pen body110. The shape of the main section 124 can be designed according toactual needs, is not limited. The main section 124 can be sphericalshape, cone shape, or any shape according to different painting styles.

Referring to FIG. 4, in one embodiment, the supporter 121 has a hollowstructure and defines a space 126 in the main section 124. The mainsection 124 has a wall with a thickness in a range from about 0.1millimeters to about 2 millimeters. The supporter 121 with a hollowstructure has a good flexibility and is easy to control the contactcapacitor between the pen head 120 and the touch panel in application.

The supporter 121 can be made of a flexible polymer material. Theflexible polymer material can be silicone elastomer, poly methylmethacrylate, polyurethane, epoxy resin, polypropylene acid ethyl ester,acrylic acid ester, polystyrene, polybutadiene, polyacrylonitrile,polyaniline, polypyrrole, polythiophene and combinations thereof. In oneembodiment, the flexible polymer material is silicone elastomer. Thesupporter 121 can be made of an electrically conductive polymer with ahigh dielectric constant, to improve the contact capacitor between thepen head 120 and the touch panel in application. The electricallyconductive polymer can be polyaniline, polypyrrole, polythiophene,polyacetylene, polyparaphenylene, poly phenylene vinylene, or anycombination of them. In one embodiment, the material of the electricallyconductive polymer is polyaniline.

Contact Layer

Referring to FIG. 3, in one embodiment, the contact layer 125 covers theentire outer surface of the main section 124 of the supporter 121. Thecontact layer 125 is located on the main section 124 and covers at leastparts of the fixing section 122. The contact layer 125 is made offlexible conductive materials. The contact layer 125 is electricallyconnected with the pen body 110 when the fixing section 122 is insertedin the hole of the fixing end 114 of the pen body 110, because thecontact layer 125 covers at least parts of the fixing section 122.

Referring to FIG. 5, in another embodiment, the contact layer 125 is aribbon-shaped layer located on part of the outer surface of the mainsection 124 of the pen head 120. The contact layer 125 helically wrapsaround the main section 124 and extends to the fixing section 122. Aradius of the contact layer 125 gradually increases along a directionfrom a tip of the main section 124 to the middle of the main section124, and then decreases from the middle of the main section 124 to thefixing section 122. In one embodiment, a groove surrounds the outersurface of the main section 124, and the contact layer 125 is located inthe groove. The contact layer 125 has a protrusion 128 extending out ofthe groove, the protrusion 128 is used to contact the touch panel inapplication. Compared to covering the whole outer surface of the mainsection 124, the contact layer 125, in FIG. 5, can cover part of theouter surface of the main section 124, which will be a lower cost.

The contact layer 125 is used to contact the touch panel and formcontact capacitor between the contact layer 125 and the touch panel,when the electrons of user's hand conduct to the touch panel by thetouch pen 100. The contact capacitor can be detected by the touch panel,and the width of lines detected by the touch panel can be controlled bythe contact area between the contact layer 125 and the touch panel. Athickness of the contact layer 125 can be in a range from about 0.1millimeters to about 2 millimeters.

In one embodiment, the contact layer 125 is a graphene layer. Thegraphene layer includes at least one layer of graphene. In oneembodiment, the graphene layer is a pure structure of graphenes.Referring to FIG. 6, the graphene is a one-atom-thick planar sheet ofsp²-bonded carbon atoms that are densely packed in a honeycomb crystallattice. A size of the graphene can be very large (e.g., severalmillimeters). However, the size of the graphene generally made is lessthan 10 microns (e.g., less than 1 micron). The graphene layer caninclude a single layer of graphene or a plurality of layers of graphene.If the graphene layer includes a plurality of layers of graphene, theplurality of layers of graphene are stacked with each other or locatedside by side. The graphene layer can be a continuous integratedstructure. The term “continuous integrated structure” can be defined asa structure that is combined by a plurality of chemical bonds (e.g., sp²bonds, sp¹ bonds, or sp³ bonds) to form an overall structure. Athickness of the graphene layer can be less than 100 nanometers. In oneembodiment, the thickness of the graphene can be in a range from about0.5 nanometers to about 100 nanometers. A thickness of the graphenelayer can be less than 1 millimeter. Because the graphene is nano-sizedmaterial with small size, the graphene layer can be fixed on the outersurface of the supporter 121 via van der Waals attractive force. Inother embodiments, the graphene layer can be fixed on the outer surfaceof the supporter 121 via conducive adhesive. Graphene has large specificsurface, and if the graphene layer is used as the conductive layer, alarge capacity can be formed between the contact layer 125 and the touchscreen, as such, a sensitivity of the contact layer 125 can be improved.Furthermore, the surface of the graphene is very smooth, the contactlayer 125 will not damage the touch screen when contact layer 125contact the touch screen.

Referring to FIG. 7, in one embodiment, the contact layer 125 includes aflexible polymer matrix 24 and a plurality of graphenes 28 dispersed inthe flexible polymer matrix 24. Some of the graphenes 28 can protrudefrom the flexible polymer matrix 24. The plurality of graphenes 28 cancontact each other to form a conductive network structure. A weightpercentage of the plurality of graphenes 28 is in a range from about 10%to about 60%. A thickness of the graphene 28 is in a range from about0.5 nanometers to about 100 nanometers.

Referring to FIG. 8, in one embodiment, the contact layer 125 includes agraphene layer 280 and a flexible polymer matrix 24. The graphene layer280 is disposed on a surface of the flexible polymer matrix 24. Thegraphene layer 280 includes a plurality of graphenes 28 stacked witheach other.

Referring to FIG. 9, in one embodiment, the contact layer 125 is acarbon nanotube composite layer that includes a flexible polymer matrix24 and a plurality of carbon nanotubes 22 dispersed therein. Theplurality of carbon nanotubes 22 connect each other and cooperativelyform a conductive network. To form the conductive network, a weightpercentage of the plurality of carbon nanotubes in the contact layer 125can range from about 5% to about 10%. The plurality of carbon nanotubes22 has a large specific surface area and high conductivity. The contactlayer 125 including the plurality of carbon nanotubes also has largespecific surface area, which can increase the contact capacitor betweenthe contact layer 125 and the touch panel on per unit area. Therefore,the pen head 120 would have a good sensitivity. The contact layer 125would also have a good flexibility and durability because carbonnanotubes are the strongest and stiffest materials yet discovered interms of tensile strength and elastic modulus respectively. In oneembodiment, at least part of the plurality of carbon nanotubes 22extrudes out of the flexible polymer matrix 24 in the contact layer 125.The at least part of the plurality of carbon nanotubes 22 extruded outof the flexible polymer matrix 24 can directly contact the touch panelin application.

The flexible polymer matrix 24 has a sheet structure with a thickness ina range from about 0.1 micrometers to about 2 millimeters. The flexiblepolymer matrix 24 can be made of a flexible polymer material such aspolydimethylsiloxane, polypropylene, poly ethyl acrylate, poly butylacrylate, polystyrene, polybutadiene, poly acrylonitrile or combinationsthereof. In one embodiment, the flexible polymer matrix 24 is made ofpolydimethylsiloxane. The flexible polymer matrix 24 can be made of anelectrically conductive polymer with a high dielectric constant, toimprove the contact capacitor between the contact layer 125 and thetouch panel in application. The electrically conductive polymer can bepolyaniline, polypyrrole, polythiophene, polyacetylene,polyparaphenylene, poly phenylene vinylene, or any combination of them.In one embodiment, the material of the electrically conductive polymeris polyaniline.

In another embodiment, the contact layer 125 can be a carbon nanotubestructure 12. The carbon nanotube structure 12 includes a plurality ofcarbon nanotubes joined by van der Waals attractive force therebetween.The carbon nanotube structure 12 can be a substantially pure structureof carbon nanotubes, with few impurities. The carbon nanotube structure12 can be a freestanding structure, that is, the carbon nanotubestructure 12 can be supported by itself without a substrate. Forexample, if at least one point of the carbon nanotube structure 12 isheld, the entire carbon nanotube structure 12 can be lifted withoutbeing destroyed.

Referring to FIG. 10, in one embodiment, a carbon nanotube compositelayer includes the flexible polymer matrix 24 and the carbon nanotubestructure 12. The flexible polymer matrix 24 and the carbon nanotubestructure 12 are sheets. The carbon nanotube structure 12 is disposed ona first surface of the flexible polymer matrix 24. The carbon nanotubestructure 12 can be at least partly embedded into the flexible polymermatrix 24 through the first surface of the flexible polymer matrix 24.

Referring to FIG. 11, in one embodiment, the carbon nanotube structure12 is disposed in the flexible polymer matrix 24. In another embodiment,the carbon nanotube structure 12 is enclosed within in the flexiblepolymer matrix 24. The flexible polymer matrix 24 is covered on surfacesof the carbon nanotube structure 12. A thickness of the flexible polymermatrix 24 covered on the layered carbon nanotube structure is less than10 millimeters. Because the thickness is very thin, surfaces of thecarbon nanotube composite layer in FIG. 11 is electrically conductive.

Carbon Nanotube Structure

The carbon nanotubes in the carbon nanotube structure 12 can be orderlyor disorderly arranged. The term ‘disordered carbon nanotube structure’refers to a structure where the carbon nanotubes are arranged alongdifferent directions, and the aligning directions of the carbonnanotubes are random. The number of the carbon nanotubes arranged alongeach different direction can be almost the same (e.g. uniformlydisordered). The carbon nanotube structure 12 has properties identicalin all directions of the carbon nanotube structure. The carbon nanotubesin the disordered carbon nanotube structure can be entangled with eachother.

The carbon nanotube structure 12 including ordered carbon nanotubes isan ordered carbon nanotube structure. The term ‘ordered carbon nanotubestructure’ refers to a structure where the carbon nanotubes are arrangedin a consistently systematic manner, e.g., the carbon nanotubes arearranged approximately along a same direction and/or have two or moresections within each of which the carbon nanotubes are arrangedapproximately along a same direction (different sections can havedifferent directions). The carbon nanotubes in the carbon nanotubestructure 12 can be single-walled, double-walled, or multi-walled carbonnanotubes. The carbon nanotube structure 12 can include at least onecarbon nanotube film. In other embodiment, the carbon nanotube structure12 is composed of one carbon nanotube film or at least two carbonnanotube films.

In one embodiment, the carbon nanotube film can be a drawn carbonnanotube film. Referring to FIG. 12, the drawn carbon nanotube filmincludes a plurality of successive and oriented carbon nanotubes joinedend-to-end by van der Waals attractive force therebetween. The drawncarbon nanotube film is a freestanding film. Each drawn carbon nanotubefilm includes a plurality of successively oriented carbon nanotubesegments joined end-to-end by van der Waals attractive forcetherebetween. Each carbon nanotube segment includes a plurality ofcarbon nanotubes substantially parallel to each other, and joined by vander Waals attractive force therebetween. Some variations can occur inthe carbon nanotube film. The carbon nanotubes in the drawn carbonnanotube film are oriented along a preferred orientation. The drawncarbon nanotube film can be treated with an organic solvent to increasethe mechanical strength and toughness of the drawn carbon nanotube filmand reduce the coefficient of friction of the drawn carbon nanotubefilm. The thickness of the carbon nanotube film can range from about 0.5nanometers to about 100 micrometers.

The carbon nanotubes in the drawn carbon nanotube structure can besingle-walled, double-walled, and/or multi-walled carbon nanotubes. Thediameters of the single-walled carbon nanotubes can range from about 0.5nanometers to about 50 nanometers. The diameters of the double-walledcarbon nanotubes can range from about 1 nanometer to about 50nanometers. The diameters of the multi-walled carbon nanotubes can rangefrom about 1.5 nanometers to about 50 nanometers. The lengths of thecarbon nanotubes can range from about 200 micrometers to about 900micrometers.

The carbon nanotube structure 12 can include at least two stacked drawncarbon nanotube films. The carbon nanotubes in the drawn carbon nanotubefilm are aligned along one preferred orientation, an angle can existbetween the orientations of carbon nanotubes in adjacent drawn carbonnanotube films, whether stacked or adjacent. An angle between thealigned directions of the carbon nanotubes in two adjacent drawn carbonnanotube films can range from about 0 degrees to about 90 degrees, suchas the angle can be about 15 degrees, 45 degrees or 60 degrees.Referring to FIG. 13, in one embodiment, the carbon nanotube structure12 includes four drawn carbon nanotube films stacked with each other,and the angel between the aligned directions of the carbon nanotubes intwo adjacent drawn carbon nanotube films is 90 degrees.

In other embodiments, the carbon nanotube film can be a flocculatedcarbon nanotube film. Referring to FIG. 14, the flocculated carbonnanotube film can include a plurality of long, curved, disordered carbonnanotubes entangled with each other. Furthermore, the flocculated carbonnanotube film can be isotropic. The carbon nanotubes can besubstantially uniformly dispersed in the flocculated carbon nanotubefilm. Adjacent carbon nanotubes are acted upon by van der Waalsattractive force to obtain an entangled structure with microporesdefined therein. Because the carbon nanotubes in flocculated carbonnanotube film are entangled with each other, the carbon nanotubestructure 12 employing the flocculated carbon nanotube film hasexcellent durability and flexibility, and can be fashioned into desiredshapes with a low risk to the integrity of the carbon nanotubestructure. A diameter of the micropores is less than 10 micrometers. Thethickness of the flocculated carbon nanotube film can range from about0.5 nanometers to about 1 micrometer.

Referring to FIG. 15, in some other embodiments, the carbon nanotubefilm can be a pressed carbon nanotube film. The pressed carbon nanotubefilm is formed by pressing a carbon nanotube array. The carbon nanotubesin the pressed carbon nanotube film are arranged along a same directionor along different directions. The carbon nanotubes in the pressedcarbon nanotube film can rest upon each other. Adjacent carbon nanotubesare attracted to each other and are joined by van der Waals attractiveforce. An angle between a primary alignment direction of the carbonnanotubes and a surface of the pressed carbon nanotube film is about 0degrees to about 15 degrees. The greater the pressure applied, thesmaller the angle obtained. If the carbon nanotubes in the pressedcarbon nanotube film are arranged along different directions, the carbonnanotube structure 12 can be isotropic. The pressed carbon nanotube filmhas identical properties in all directions substantially parallel to asurface of the carbon nanotube film. A thickness of the pressed carbonnanotube film can range from about 0.5 nanometers to about 1 micrometer.

In one embodiment, the carbon nanotube structure 12 can be a carbonnanotube array that includes a plurality of ordered carbon nanotubes.The carbon nanotubes of the carbon nanotube array are oriented along asame direction and are perpendicular to a substrate which they grow on.A thickness of the carbon nanotube array ranges from about 0.5nanometers to about 100 microns.

Referring to FIG. 16 and FIG. 17, in some embodiments, the carbonnanotube structure 12 can include at least one carbon nanotube wirestructure 152 located on the outer surface of the supporter 121.Referring to FIG. 16, in one embodiment, if the carbon nanotubestructure 12 is a single carbon nanotube wire structure 152, the carbonnanotube structure 12 can be twisted around the outer surface of thesupporter 121. Referring to FIG. 17, in other embodiment, if the carbonnanotube structure 12 includes a plurality of carbon nanotube wirestructures 152, the plurality of carbon nanotube wire structures 152 canbe crossed with each other or woven with each other to form a netstructure. The net structure covers the outer surface of the supporter121.

The carbon nanotube wire structure 152 includes a plurality of carbonnanotubes joined end to end by van der Waals attractive forcetherebetween. The carbon nanotube wire structure 152 can be asubstantially pure structure of carbon nanotubes, with few impurities.The carbon nanotube wire structure 152 can be a freestanding structure.The carbon nanotubes in the carbon nanotube wire structure 152 can besingle-walled, double-walled, or multi-walled carbon nanotubes.

The carbon nanotube structure 152 includes at least one carbon nanotubewire 150. The carbon nanotube wire 150 includes a plurality of carbonnanotubes. The carbon nanotube wire 150 can be a pure wire structure ofcarbon nanotubes. The carbon nanotube wire 150 includes a plurality ofpores defined by adjacent carbon nanotubes. Size of the pores is lessthan 10 micrometers. Referring to FIG. 18, the carbon nanotube wirestructure 152 can include a plurality of carbon nanotube wires 150parallel with each other. The plurality of carbon nanotube wires 150 canbe fixed together via adhesive. Referring to FIG. 19, in otherembodiments, the carbon nanotube wire structure 152 includes a pluralityof carbon nanotube wires 150 twisted with each other.

The carbon nanotube wire 150 can be untwisted or twisted. Referring toFIG. 20, the untwisted carbon nanotube wire includes a plurality ofcarbon nanotubes substantially oriented along a same direction (i.e., adirection along the length direction of the untwisted carbon nanotubewire). The untwisted carbon nanotube wire can be a pure structure ofcarbon nanotubes. The untwisted carbon nanotube wire can be afreestanding structure. The carbon nanotubes are substantially parallelto the axis of the untwisted carbon nanotube wire. In one embodiment,the untwisted carbon nanotube wire includes a plurality of successivecarbon nanotube segments joined end to end by van der Waals attractiveforce therebetween. Each carbon nanotube segment includes a plurality ofcarbon nanotubes substantially parallel to each other, and combined byvan der Waals attractive force therebetween. The carbon nanotubesegments can vary in width, thickness, uniformity and shape. Length ofthe untwisted carbon nanotube wire can be arbitrarily set as desired. Adiameter of the untwisted carbon nanotube wire ranges from about 50nanometers to about 100 micrometers.

Referring to FIG. 21, the twisted carbon nanotube wire includes aplurality of carbon nanotubes helically oriented around an axialdirection of the twisted carbon nanotube wire. The twisted carbonnanotube wire can be a pure structure of carbon nanotubes. The twistedcarbon nanotube wire can be a freestanding structure. In one embodiment,the twisted carbon nanotube wire includes a plurality of successivecarbon nanotube segments joined end to end by van der Waals attractiveforce therebetween. Each carbon nanotube segment includes a plurality ofcarbon nanotubes substantially parallel to each other, and combined byvan der Waals attractive force therebetween. The length of the carbonnanotube wire can be set as desired. A diameter of the twisted carbonnanotube wire can be from about 50 nanometers to about 100 micrometers.Furthermore, the twisted carbon nanotube wire can be treated with avolatile organic solvent after being twisted. After being soaked by theorganic solvent, the adjacent substantially parallel carbon nanotubes inthe twisted carbon nanotube wire will bundle together, due to thesurface tension of the organic solvent when the organic solventvolatilizes. The density and strength of the twisted carbon nanotubewire will increase.

In one embodiment, the carbon nanotube wire structure 152 includes aplurality of carbon nanotube composite wires. The carbon nanotubecomposite wire is made by adding polymer material in the pores of thecarbon nanotube wire 150. The tensile strengths can be increased afteradding the polymer material in the pores of the carbon nanotube wire150. The polymer material can be polyacrylonitrile, polyvinyl alcohol(PVA), polypropylene (PP), polystyrene (PS), polyvinylchloride (PVC),polyethylene terephthalate (PET), or combinations thereof.

In another embodiment, the carbon nanotube composite wire can also bemade by adding metal material in the pores of the carbon nanotube wire150. The metal material can coat on outer surface of the carbonnanotubes in the carbon nanotube wire 150. The metal material can becopper (Cu), silver (Ag), or combination thereof.

Carbon Nanotube Composite Layer

Referring to FIG. 22, in one embodiment, the carbon nanotube structure12 is a carbon nanotube array dispersed in the flexible polymer matrix24 and forms the carbon nanotube composite layer. The carbon nanotubearray includes a plurality of carbon nanotubes 22 oriented a long a samedirection and parallel with each other. Referring to FIG. 23, in oneembodiment, the carbon nanotubes 22 of the carbon nanotube array extrudeout of the flexible polymer matrix 24. The parts of the carbon nanotubes22 extruding out of the flexible polymer matrix 24 are equal to or lessthan 10 micrometers.

Referring to FIG. 24, in one embodiment, the carbon nanotube compositelayer made of the contact layer 125 includes a carbon nanotube structure12 and a conductive material layer 226. The carbon nanotube structure 12works as a framework. The conductive material layer 226 is coated on thesurfaces of the carbon nanotube structure 12. That is, the conductivematerial layer 226 is supported by the carbon nanotube structure 12.

The carbon nanotube structure 12 includes a plurality of carbonnanotubes 22 and micropores 225. The plurality of carbon nanotubes 22 isassembled together by Van der Waals attractive forces. The micropores225 are defined between the adjacent carbon nanotubes 22 of the carbonnanotube structure 12. A size of each micropore 225 can be less than 5micrometers. In one embodiment, the size of each micropore is in a rangefrom about 50 nanometers to about 500 nanometers. A size of themicropore 225 represents the maximum distance between two points on themicropore 225. The carbon nanotube structure 12 includes a plurality ofmicropores 225.

The conductive material layer 226 is coated on the micropores 225 carbonnanotube structure 12. The conductive material layer 226 wraps aroundthe carbon nanotubes 22 to form a tubular coating layer structure. Here,the individual carbon nanotube 22 and the carbon nanotube structure 12serve as the core and the template. In one embodiment, the conductivematerial layer 226 is disposed on the whole surface of the carbonnanotube structure 12, which means that the surface of each carbonnanotube 22 is coated by the conductive material layer 226.

The conductive material layer 226 can be an electrically conductivepolymer layer made of a material such as polyaniline, polypyrrole,polythiophene, polyacetylene, polyparaphenylene, poly phenylenevinylene, or any combination thereof. A thickness of the electricallyconductive polymer layer is from about 30 nanometers to about 150nanometers. A weight percentage of the electrically conductive polymermaterial in the carbon nanotube composite layer is in a range from about5% to about 80%. In one embodiment, the material of the conductivematerial layer 226 is polyaniline, and the weight percentage of theconductive material layer 226 in carbon nanotube composite layer is in arange from about 5% to about 20%.

The conductive material layer 226 can also be a metal layer made ofmetal, such as copper (Cu), silver (Ag), or combination thereof. Athickness of the metal layer electrically conductive polymer layer canbe from about 1 nanometer to about 20 nanometers.

In some other embodiments, a middle layer can be located between thecarbon nanotubes 22 and the metal layer. The middle layer has goodwetting property with the carbon nanotube 22, and can combine tightlywith the carbon nanotubes 22. The metal layer is located on an outersurface of the middle layer. A material of the middle layer can benickel, palladium or titanium. A thickness of the middle layer can be ina range from about 4 nanometers to about 10 nanometers.

The carbon nanotube composite layer has good conductivity and cantransmit current fast, as such, if the carbon nanotube composite layeris used as the contact layer 125 of the pen head 120. The touch pen 100can have a high reaction speed.

Referring to FIG. 25, in the carbon nanotube composite layer of someembodiments, the carbon nanotube structure 12 includes a plurality ofcarbon nanotube wire structures 152 disposed on a surface of theflexible polymer matrix 24. The plurality of carbon nanotube wirestructures 152 is parallel to each other. Referring to FIG. 26, in someother embodiments, the carbon nanotube structure 12 includes a pluralityof carbon nanotube wire structures 152 crossed with each other to form anetwork, and disposed on a surface of the flexible polymer matrix 24.

Pen Head with Different Shapes for Different Painting Styles

Referring to FIG. 27, in one embodiment, a touch pen 200 includes a penbody 110 and a Chinese brush-shaped pen head 220. The Chinese brushshaped pen head 220 is fixed on and electrically connected with the penbody 110. The touch pen 200 can be used in painting Chinese painting orwriting Chinese traditional handwriting or calligraphy on touch panel inapplication.

Referring to FIG. 28, in one embodiment, the Chinese brush-shaped penhead 220 includes a plurality of carbon nanotube wire structures 152assembled with each other. Each of the plurality of carbon nanotube wirestructures 152 includes a first end 252 and a second end 254. The firstends 252 are aligned and assembled with each other and fixed to thefixing end 222 of the pen head 220. The fixing end 222 is used to fixthe Chinese brush-shaped pen head 220 to the pen body 110. The firstends 252 can be electrically connected with the pen body 110 when thefixing end 222 is fixed on one end of the pen body 110. To ensure theshape of the Chinese brush-shaped pen head 220, the length of theplurality of carbon nanotube wire structures 152 decrease in a directionfrom the middle axis of the Chinese brush shaped pen head 220 to theouter surface of the Chinese brush shaped pen head 220. The partsbetween the first end 252 and the second end 254 of the carbon nanotubewire structures 152 can be adhered by a conductive polymer or conductiveadhesive.

In another embodiment, the pen head 220 can be made by a hot-pressingmethod in a Chinese brush shaped die. Carbon nanotubes is put into theChinese brush shaped die and heated in a predetermined temperature. Thecarbon nanotubes are stacked and crossed with each other, and joined byVan der Walls attractive force to form a whole structure. A plurality ofmicrospores is defined in the Chinese brush-shaped pen head 220, betweenthe adjacent carbon nanotubes. A diameter of the plurality ofmicrospores is less than 10 micropores. Therefore, the Chinesebrush-shaped pen head 220 has good flexibility and large specificsurface area. The contact capacitor between the pen head 220 and thetouch panel in application can be improved in application. It isunderstood that the Chinese brush-shaped pen head 220 can be made of thecarbon nanotube structure 12 by hot-pressing method in the die.

Referring to FIG. 29, in one embodiment, a touch pen 300 includes a penbody 110 and an oil brush-shaped pen head 320. The touch pen 300 withthe oil brush-shaped pen head 320 can be used in painting oil paintingon touch panel in application.

Referring to FIG. 30, in one embodiment, a touch pen 400 includes thepen body 110 and a pen head 420. The pen head 420 includes a fixingsection 422 and a main section 424. The fixing section 422 is used tofasten the pen head 120 to the fixing end 114 of the pen body 110. Aspace 426 is defined in the main section 424. The main section 424 has awall with a thickness in a range from about 0.1 millimeter to about 2millimeters. The pen head 420 is made of the carbon nanotube compositelayer described above. Furthermore, a liquid with high permittivity canbe stuffed in the space 426, the capacitor between the main section 424and the touch panel would increase in application. The liquid with highpermittivity can be purified water or formic acid.

It is understood that the liquid with high permittivity can be stuffedin the space 126 of the main section 124 in FIG. 4.

The touch pen disclosed above can be used to operate on a capacitivetouch panel screen.

It is to be understood that the described embodiments are intended toillustrate rather than limit the disclosure. Any elements described inaccordance with any embodiments is understood that they can be used inaddition or substituted in other embodiments. Embodiments can also beused together. Variations may be made to the embodiments withoutdeparting from the spirit of the disclosure. The disclosure illustratesbut does not restrict the scope of the disclosure.

1. A touch pen comprising: a body; and a head fixed on one end of thebody and electrically connected with the body, wherein the headcomprises a plurality of carbon nanotubes.
 2. The touch pen as claimedin claim 1, wherein the head is soft and flexible.
 3. The touch pen asclaimed in claim 2, wherein the plurality of carbon nanotubes arestacked and crossed with each other and joined by van der Wallsattractive force and form a freestanding structure.
 4. The touch pen asclaimed in claim 3, wherein a plurality of pores is defined betweenadjacent carbon nanotubes of the plurality of carbon nanotubes.
 5. Thetouch pen as claimed in claim 4, wherein a diameter of the plurality ofpores is less than or equal to 10 micrometers.
 6. The touch pen asclaimed in claim 3, wherein the plurality of carbon nanotubes ismulti-walled carbon nanotubes.
 7. The touch pen as claimed in claim 1,wherein the body is a tubular structure.
 8. The touch pen as claimed inclaim 7, wherein the body comprises metal.
 9. The touch pen as claimedin claim 1, wherein the one end of the body defines a hole having aninternal thread.
 10. The touch pen as claimed in claim 9, wherein thehead is fixed in the one end of the body and engaged with the internalthread.
 11. The touch pen as claimed in claim 1, wherein the head has aChinese-brush shape.
 12. The touch pen as claimed in claim 1, whereinthe head has an oil-brush shape.
 13. A touch pen comprising: a body; anda head fixed on one end of the body and electrically connected with thebody, wherein the head is made of a plurality of carbon nanotubescrossed with each other, and joined by van der Walls attractive forces.14. The touch pen as claimed in claim 13, wherein a plurality of poresis defined between adjacent carbon nanotubes of the plurality of carbonnanotubes.
 15. The touch pen as claimed in claim 14, wherein a diameterof the plurality of pores is less than or equal to 10 micrometers. 16.The touch pen as claimed in claim 13, wherein the body comprises metal.17. The touch pen as claimed in claim 13, wherein the one end of thebody defines a hole having an internal thread.
 18. The touch pen asclaimed in claim 17, wherein the head is fixed on the one end of thebody and engaged with the internal thread.
 19. The touch pen as claimedin claim 13, wherein the head has a Chinese-brush shape.
 20. The touchpen as claimed in claim 13, wherein the head has an oil-brush shape.